The present invention relates to connectors for electrically connecting one circuit board with another, and more particularly to such a connector which facilitates entry and withdrawal of the circuit boards.
Connectors for the electrical interconnection of printed circuit boards have heretofore been proposed. Traditionally, connectors of this type include a housing which forms a slot sized to receive a daughter board. A plurality of contacts are retained in the housing and include flexible ends that can be spread apart to receive the daughter board and engage the conductors thereof. Other ends of the contacts project from the housing and are adapted for connection with a mother board. In some instances the flexible ends of the contacts are forcefully spread apart upon being contacted by the daughter board. However, the cumulative resistance offered by the contacts can be difficult to overcome and may result in damage occurring to the circuit boards.
With this difficulty in mind, connectors have been proposed in which the resilient ends of the contacts can be spread apart prior to insertion or withdrawal of the daughter board. This usually involves some sort of manually actuable camming member which urges the contacts open against an inherent closing bias, or urges them closed against an inherent opening bias. Exemplary of connectors of this type are those disclosed in Hartmann U.S. Pat. No. 3,665,370 issued May 23, 1972; Lightner U.S. Pat. No. 3,848,222 issued Nov. 12, 1974; Carter U.S. Pat. No. 3,865,457, issued Feb. 11, 1975; Pritulsky U.S. Pat. No. 3,897,991 issued Aug. 5, 1975; and Yeager et al. U.S. Pat. No. 3,899,234 issued Aug. 12, 1975.
Such connectors, often referred to as zero force insertion connectors, are intended to facilitate the entry and removal of the daughter boards and minimize the strain on the circuit boards.
It is desirable that connectors of this or any other type be of minimal dimension, especially in the lateral direction, or width, to maximize the number of connectors which can be mounted to a mother board. The presence of a camming mechanism may tend to produce an excessive increase in width.
It is further important that the durability of the connector be maintained. That is, any possible fatigue-induced breakage resulting from repeatedly camming the contacts open or closed, should be avoided.
For example, in one instance a connector has been heretofore proposed as described in an article presented at the Ninth Annual Connector Symposium Proceedings held Oct. 21, 1976 at Cherry Hill, N.J., the article entitled "A new Zero-Insertion Force Card-Edge Connector" by R. Cobaugh and A. Taylor, pages 400-401, and in an AMP Brochure designated as Data Sheet Number 76-376, Revised Oct., 1976, pages 15-20 to 15-24. In this connector, inwardly-biased flexible ends of the contacts are mounted in the upper portion of a pair of side walls of the connector. The lower end of each side wall is hooked beneath the underside of a stationary base part the connector to provide a hinge about which the side wall may swing. A camming bar is slidably mounted between the base and the side wall so that when the bar is slid longitudinally, the side wall is caused to swing outwardly about its hinge, thereby spreading the contacts apart. One characteristic of this type of connector is the increased width resulting from the presence of the swinging side wall, which is located laterally outwardly of the camming bar. Furthermore, in order to remove the side walls from the base for servicing purposes, it is necessary to separate the side walls from not only the contacts, but from the hooked connection with the base.
It is, therefore, an object of the present invention to provide a novel connector for facilitating entry and removal of a circuit board.
It is another object of the invention to provide such a novel connector of relatively narrow width.
It is a further object of the invention to provide such a novel connector which is highly durable and which minimizes the effort needed to actuate the contacts.
It is an additional object of the invention to provide a novel connector which is easily disassembled for servicing.
It is still another object of the invention to provide a zero force insertion connector which employs a camming bar that is both slidably and swingably mounted to a base.